Watercraft

ABSTRACT

The invention relates to a watercraft, particularly a river boat, with a hull for receiving useful devices and with propulsion units for generating a driving force and which are located on the hull. The watercraft according to the invention is characterized in that guiding elements are provided in the bow area on the underside of the hull, which have a vertical, forwardly tapering wedge shape, that the propulsion units in the bow area are set back from the wedge-shaped guiding elements, that between the guiding elements is provided a partial area of the hull constructed in the form of a horizontal wedge and that the propulsion units are pivotably mounted.

The present invention relates to a watercraft, particularly a riverboat, according to the preamble of claim 1.

Such watercraft are e.g. known from DE 37 12 534 A1 and have a hull forreceiving useful devices, together with propulsion units located on thehull for generating a driving force. In the bow area of the underside ofthe hull are also provided guiding elements, which in each case have avertical, forwardly tapering wedge shape. Finally, between the guidingelements, is provided a partial area of the hull in the form of ahorizontal wedge.

In the case of river craft the flow round the hull in shallow, laterallylimited shipping channels becomes problematical with increasing speedand beam.

A conventional vessel bow mainly displaces the water laterally outwardsand ever smaller, to almost no water is passed under the bottom of thevessel.

The vessel so-to-speak is sucked towards the bottom of the shippingchannel and there is a rise in the lateral flow rate. The water thenflows away ever less well and the boat starts to virtually push a watermountain in front of it. This mountain can only flow away between theside of the vessel and the bank, which once again leads to an everhigher lateral flow rate. Together with the ever smaller water quantitypast under the bottom of the vessel in the stern direction, this interalia considerably reduces the efficiency of the centrally rearwardlylocated drive propeller or propellers. In addition, a powerfultransverse wave builds up behind the vessel and to a certain extentdetains the vessel.

Relative to the availability of water for driving the vessel, inprinciple optimum propulsion conditions would exist on the bow side, butuse cannot be made thereof with conventional vessel bow shapes. Insteadof this an attempt is made in the stern by using complicated shapes andcomplex propulsion geometries, to gain an optimum from the in principleinferior afflux conditions. The action of transverse thrust units andhorizontally positioned propeller/pump systems in the prow, such as arenowadays used in river boats, is naturally also significantly reducedthrough the high flow rates or the in extreme cases non-existent affluxof water under the boat.

Further watercraft with guiding elements are described in DE 29 28 634B1 and DE 696 12 995 T2.

The object of the invention is to provide a watercraft of theaforementioned type, in which only part of the water is displaced to theside by the bow and in which the efficiency for the drive units issignificantly improved.

This object is achieved by the watercraft having the features of claim1.

According to the invention the watercraft of the aforementioned type isfurther developed in that the propulsion units in the bow area are setback with respect to the guiding elements and said propulsion units arepivotably mounted.

Advantageous developments of the inventive watercraft form the subjectmatter of subclaims.

A first essential idea of the invention is to provide in the bow area ofthe watercraft a plurality of guiding elements, which have a verticalwedge shape and taper in the forwards direction. As a result of saidguiding elements a considerable proportion of the displaced water isdisplaced inwards and not outwards.

A further fundamental idea is to construct a partial area locatedbetween the wedge-shaped guiding elements in the form of a horizontalwedge, which also tapers upstream. As a result of a wedge-shaped partialarea, the water displaced inwards by the guiding element can be passedunder the hull.

A third fundamental idea is to place the propulsion units in the bowarea so as to be set back with respect to the guiding elements. Thisclearly improves the efficiency of the propulsion units.

Finally, according to a fourth fundamental idea the propulsion units arepivotably mounted. Thus, it is e.g. possible to specifically adapt asetting angle of the propulsion units to the speed of travel. This leadsto important advantages with regards to the efficiency of the driveunits.

A first essential advantage of the invention is that, unlike thesituation in the stern, water is supplied at the front with the dynamicpressure to the propulsion units. The dynamic pressure is then reducedover the propulsion units in the bow area, which gives the expectation,relative to the wave pattern in the bow area, of a similar effect to abulb bow in conventional boat shapes.

A further advantage of the invention is that with this novel bow shapethere is a significantly reduced wave formation, which greatly reducesdamage to the banks compared with conventional river boats.

In a preferred development of the invention the guiding elements areprovided starboard and port. A particularly large proportion of thedisplaced water can then pass under the watercraft.

A particularly good manoeuvrability of the watercraft is obtained if thepropulsion units, which can appropriately be constructed as drivepropellers, are mounted so as to pivot about a vertical axis. This alsomakes possible an angular adjustment of the drive propellers as afunction of the speed of travel.

The partial area between the guiding elements can in this way be soconstructed that it essentially has the bow shape of a sea sledge. Thewedge-shaped guiding elements can be constructed in the manner of theprow geometry of a catamaran or semi-catamaran. These are known hullshapes, so that in this connection use can be made of known technologiesand costs can be saved.

An improvement to the flow characteristics can be obtained if at leastone of the guiding elements tapers rearwards in the vertical wedgeshape. Particularly good results are obtained if in the case of at leastone guiding element the stern-side wedge shape is made more blunt orobtuse than the bow-side wedge shape.

The efficiency of the propulsion units can be improved if the guidingelements have recesses in which the propulsion units are located.Particularly good results are obtained if the propulsion units arelocated in areas where a large number of flow lines converge, e.g.directly behind a stern-side edge of the guiding elements.

Obviously propulsion units can also be provided in the stern area of thehull. This brings about an even greater watercraft manoeuvrability.

The passing through of water under the hull can be improved if,particularly on the port and starboard sides, wedge-shaped guidingelements are also provided in the hull stern area. These guidingelements can also taper rearwards in the vertical wedge shape.Optionally such guiding elements can also be provided in the centralarea of the hull or also distributed over the entire hull length.

The passing of water quantities beneath the hull can also be improved bya device for smearing with air bubbles. These can in particular bedevices of the type described in DE 103 07 795.

Preferably openings, e.g. water supply slots, are provided on theguiding elements in order to supply water to the propulsion units. Thesewater supply slots are appropriately positioned lengthwise to thedirection of travel and this also prevents flotsam or ice being forcedinto the drive units.

The geometry of the novel, innovative bow shape is eminently suitablefor ice navigation and then the hull, particularly the bow-side guidingelements, are preferably constructed for ice breaking purposes.

The catamaran hulls cut the ice covering by pressure from above. Onlyroughly half the broken ice flows have to be laterally displaced and theother half is moved under the hull and is passed rearwards inlow-friction manner via the e.g. air bubble-smeared bottom. A specificstern shape then prevents the rear propulsion units being damaged by iceflows. In order to protect the bow-side propulsion units during such icenavigation, there are provided appropriately covering devices for the atleast partial covering of the recesses in the guiding elements in whichthe propulsion units are located.

During ice navigation with a limited draught, the front propulsion unitsare switched off and an outer tunnel slot on each outside is coveredfrom the front up to the level of the propulsion units with the aid of arail-guided covering device, which can be in the form of a bow door.Thus, when travelling in ice with the vessel empty or in ballast, no iceflows can enter the front propulsion tunnel.

Thus, an essential basic principle of the present invention is theangularity of the drive units in conjunction with the geometry of thebow shape. The propeller thrust results in a forward thrust andpropeller wake friction on the side of the vessel can be largelyavoided. The setting angle of the front, i.e. bow-side drive units canalways be adapted in optimum manner to the vessel speed. Particularlygood results can be obtained if the drive units are rotatable about avertical axis and thus can consequently be set at random angles as afunction of the speed of travel.

With the watercraft according to the invention is also created a bowshape, in which in planned manner a part of the inflowing water isdeflected under the ship and to the drives instead of outwards to theside only part of the inflowing water is displaced laterally outwards.

Further characteristics and advantages of the inventive watercraft aredescribed in greater detail hereinafter relative to the attacheddrawings, wherein show:

FIG. 1 a perspective view of the bow shape of a watercraft according tothe invention;

FIG. 2 a vertical sectional view in the direction of the longitudinalaxis of the watercraft of FIG. 1;

FIG. 3 a horizontal sectional view of the watercraft of FIG. 1; and

FIG. 4 another horizontal sectional view of the watercraft of FIG. 1.

FIGS. 1 to 4 show an embodiment of a watercraft 10 according to theinvention in the form of a river boat 10. Equivalent components are ineach case given the same reference numerals.

In each case it is shown a bow area 18 of the inventive river craft 10.Random useful devices 14 can be placed on a top surface 50 of hull 12.Wedge-shaped guiding elements 24 according to the invention are providedport and starboard on the underside 22 of the hull 12 facing the water20. According to the invention the guiding elements 24 taper forwards tobow-side wedge shapes 26, which in the embodiment shown here terminatewith a bow-side hull end 48 and are directed substantially transverselyto the water surface 34. Thus, the shape of the guiding elements 24 canbe looked upon as a vertical wedge shape.

As is apparent from the horizontal sectional view of FIG. 3, theinwardly positioned lateral faces of the wedge-shaped guiding elements24 bound a cross-sectionally, substantially rectangular partial area 28.According to the invention said partial area and as can be particularlyclearly seen in the perspective view of FIG. 1 and vertical sectionalview of FIG. 2, can be constructed as a horizontal wedge 30, whichtapers in the direction of the bow-side end 48 of hull 12, i.e. in theforwards direction.

FIG. 3 also shows openings 38 over which water can be supplied to thepropulsion units 16, as is shown in greater detail in FIG. 4. Theseopenings are positioned lengthwise to the travel direction, whichlargely prevents a forcing of flotsam or ice into the drive units 16,32.

As a result of the cooperation between the laterally positioned,wedge-shaped guiding elements 24 and the partial area 28 constructed asa horizontal wedge, a considerable proportion of the water striking thehull on the bow-side is passed between the guiding elements 24 andconsequently under the hull 12. The substantially parallel, inwardlypositioned lateral faces of the wedge-shaped guiding elements 24 lead toa particularly smooth flow behaviour, because eddy formation can belargely prevented.

Recesses 42 are provided in both guiding elements 24 for the receptionof drive propellers 32 as propulsion units 16. The drive propellers 32are pivotably mounted about a vertical axis, i.e. about an azimuthangle. Preferably the drive propellers 32 can be rotated over at least180°, but in principle larger rotation angles can be obtained. In thisway and in particular if there are corresponding drive units on thestern side, excellent manoeuvrability of the river craft 10 according tothe invention can be obtained.

The guiding elements 24 taper rearwards to the stern-side wedge shapes36 which, compared with the bow-side wedge shapes, have a more obtuseconstruction 26 and also extend substantially transversely to the watersurface 34, i.e. also constituting vertical wedge shapes.

The particularly advantageous flow pattern attainable with the inventivebow shape is illustrated diagrammatically in FIG. 4 with the aid of aplurality of arrows 46. In conjunction with the partial area 28constructed as a horizontal wedge 30 and the lateral faces of thewedge-shaped guiding elements 24, as a result of the construction of thebow and stern-side wedge shapes 26, 36 of guiding elements 24 a flowpattern is obtained in which a particularly large number of flow linesconverge behind the stern-side wedge shapes 26. Thus, the drivepropellers 32 are located precisely where a particularly large number offlow lines converge. Apart from the particularly smooth flow behaviourand limited wave formation, in the invention this leads to a clearimprovement to the efficiency of the propulsion units 32.

Thus, according to the invention, based on the bow shape of the seasledge in conjunction with the front geometry of a semi-catamaran, therepresented bow shape is implemented in conjunction with azimuthing,vertical propeller drives. Even in the case of very shallow water, withthe novel bow geometry only part of the water in front of the vessel isdisplaced to the side from the bow and the remainder is guided by thebow under the vessel or supplied to the front drive propellers.

Thus, the bow essentially comprises three wedges, in each case onevertical wedge on the outside, similar to the prow geometry of acatamaran (or semi-catamaran) and in the centre between them ahorizontal wedge, similar to the bow shape of a sea sledge.

The outer bow parts, i.e. the catamaran wedges, displace part of thewater outwards in front of the vessel, whereas the horizontal wedgeshape of the sea sledge guides the water between the catamaran hullparts under the vessel and to the propulsion units located outside inthe catamaran hull parts, which are mainly constructed as vertical,azimuthing propellers.

The propulsion units are in each case so positioned in a type of tunnelin the lateral bow hulls, that they can be pivoted over at least 180°,i.e. can also exert a thrust to the side and forwards, e.g. for slowingdown the vessel.

1-13. (canceled)
 14. Watercraft, having a hull for receiving usefuldevices, in which on an underside of hull in a bow area and both to portand starboard is in each case provided a guiding element, which in eachcase has a vertical, forwardly tapering wedge shape, in which betweenthe two guiding elements is provided a partial area of hull constructedin the form of a horizontal wedge and with propulsion units located onthe hull for generating a driving force, wherein in the bow area in eachcase at least one propulsion unit is set back from the guiding element,the propulsion units are pivotably mounted and the guiding elements haverecesses in which are located the propulsion units.
 15. Watercraftaccording to claim 14, wherein the propulsion units are pivotable abouta vertical axis.
 16. Watercraft according to claim 14, wherein thepropulsion units are constructed as drive propellers.
 17. Watercraftaccording to claim 14, wherein the partial area essentially has the bowshape of a sea sledge.
 18. Watercraft according to claim 14, wherein atleast one of the guiding elements tapers rearwards in the form of avertical, stern-side wedge.
 19. Watercraft according to claim 18,wherein the stern-side wedge shape of at least one guiding element ismore obtuse than the bow-side wedge shape.
 20. Watercraft according toclaim 14, wherein additional propulsion units are provided in the sternarea of the hull.
 21. Watercraft according to claim 14, wherein in thestern area of the hull are provided guiding elements with a verticalwedge shape, which taper rearwards.
 22. Watercraft according to claim14, wherein covering devices are provided for the at least partialcovering of recesses.
 23. Watercraft according to claim 14, wherein thehull is constructed for ice breaking purposes.
 24. Watercraft accordingto claim 14, wherein a setting angle of the propulsion units isadaptable to a speed of travel.
 25. Watercraft according to claim 14,wherein on the guiding elements are provided water supply slots for thepropulsion units, the water supply slots being provided lengthwise tothe direction of travel.
 26. Watercraft according to claim 14, whereinport and starboard, in the stern area of the hull are provided guidingelements with a vertical wedge shape, which taper rearwards. 27.Watercraft according to claim 14, wherein the bow-side guiding elementsof the hull are constructed for ice breaking purposes.
 28. Watercraftaccording to claim 14, including a device for smearing with air bubbles.29. River boat, having a hull for receiving useful devices, in which onan underside of hull in the bow area and both to port and starboard isin each case provided a guiding element, which in each case has avertical, forwardly tapering wedge shape, in which between the twoguiding elements is provided a partial area of hull constructed in theform of a horizontal wedge and with propulsion units located on hull forgenerating a driving force, wherein in the bow area in each case atleast one propulsion unit is set back from the guiding element, thepropulsion units are pivotably mounted and the guiding elements haverecesses in which are located the propulsion units.